Phase‐Transition‐Induced VO2 Thin Film IR Photodetector and Threshold Switching Selector for Optical Neural Network Applications

Abstract As the architecture of choice for future artificial‐intelligent systems, the ideas of in‐memory‐ and in‐sensor‐computing paradigms based on non‐von‐Neumann architecture possess broad application prospects such as neuromorphic and sensor‐memory‐processor fusion systems. At the same time, these promising applications put diversified and strict requirements on the device performances, such as fast response to external signals, robust data security, and 3D integration potential. In this work, Au@VO 2 IR photodetectors and Ti/Au/VO 2 /Ti/Au threshold switching selectors are constructed, where the VO 2 thin films are realized by magnetron sputtering and water‐vapor assisted post‐annealing. Fast IR response is achieved in Au@VO 2 photodetectors through a surface plasmon resonance‐assisted metal‐insulator transition. Furthermore, electroforming‐free, tunable threshold voltage, steep switching slope, and selectivity of more than two orders of magnitude are observed in Ti/Au/VO 2 /Ti/Au threshold switching selector. Combining the functionalities of photodetection and selector, a VO 2 ‐based optical convolution engine demonstrates accurate and secure image‐processing capability. These VO 2 ‐based devices are demonstrated as promising candidates for novel non‐volatile memory, neuromorphic computing and sensor‐memory‐processor fusion applications.